content: /*
   * Copyright 2011-2016 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package ix;
  
  /**
   * A function callback with four input values and one output value.
   * @param <T> the first input value type
   * @param <U> the second input value type
   * @param <V> the third input value type
   * @param <W> the fourth input value type
   * @param <R> the output value type
   */
  public interface IxFunction4<T, U, V, W, R> {
      /**
       * Applies a function to the input values and returns an output value.
       * @param t the first input value
       * @param u the second input value
       * @param v the third input value
       * @param w the fourth input value
       * @return the output value
       */
      R apply(T t, U u, V v, W w);
  }
  